Australian authorities have declared that they are doing "everything possible" to fight coronavirus outbreaks in aged care facilities in the state of Victoria.

As of Wednesday there were 804 active cases relating to outbreaks across aged care facilities in Victoria, and Prime Minister Scott Morrison declared the situation a "health crisis" on Tuesday in a press conference.

Nick Coatsworth, the deputy chief medical officer (CMO), said on Wednesday that governments across the country have committed resources to help fight the outbreaks in more than 80 facilities.

"I can tell you that as of today, everything possible is being done," he told Australian Broadcasting Corporation (ABC) television.

"Now, the numbers of cases in some facilities is substantial and that is going to take some time to get on top of, but we have seen that there is an Australian Medical Assistance Team (AUSMAT) going down there of clinical leaders to help with that leadership gap that we have got."

St Basil's Home for the Aged, a nursing home in Melbourne's northern suburbs, has been identified as one of the hardest-hit facilities with nine deaths. And so far 89 cases have been linked to the facility, according to the update from the Department of Health and Human Services in Victoria on Wednesday.

Families of residents at the facility have complained that they waited days for information from the facility about the conditions of their relatives.

The Australian Medical Association (AMA) has called for a royal commission into the aged care crisis while Alison McMillan, Australia's chief nursing and midwifery officer, has said she has "considerable concerns" about the care given to residents at St Basil's.

"On Sunday I went in and we added additional resources to that facility as we were moving significant numbers out as well," she told ABC radio on Wednesday.

"I acknowledge that there were some occasions where care wasn't as good as I would want to see."